See also

References

Lifetime risk estimates calculated by the Statistical Information Team at Cancer Research UK. Based on Office for National Statistics (ONS) 2016-based Life expectancies and population projections. Accessed December 2017, and Smittenaar CR, Petersen KA, Stewart K, Moitt N. Cancer Incidence and Mortality Projections in the UK Until 2035. Brit J Cancer 2016.

About this data

Data is for UK, past and projected cancer incidence and mortality and all-cause mortality rates for those born in 1961, ICD-10 C18-C20.

The calculations used past and projected cancer incidence and mortality and all-cause mortality rates for those born in 1961 to project risk over the lifetime of those born in 1961 (cohort method).[1] Projections are based on observed incidence and mortality rates and therefore implicitly include changes in cancer risk factors, diagnosis and treatment.

International Agency for Research on Cancer (IARC) and World Cancer Research Fund/American Institute for Cancer Research (WCRF/AICR) classifications.

a IARC classifies evidence on X radiation and gamma radiation as sufficient for colon and limited for rectum; b WCRF/AICR classifies evidence on physical activity as convincing for colon, no conclusion was drawn for rectum.

International Agency for Research on Cancer (IARC) and World Cancer Research Fund/American Institute for Cancer Research (WCRF/AICR) classify the role of this risk factor in cancer development.[1,2] 13% of bowel cancer cases in the UK are caused by eating processed meat.[3]

International Agency for Research on Cancer (IARC) and World Cancer Research Fund/American Institute for Cancer Research (WCRF/AICR) classify the role of this risk factor in cancer development.[1,2] 11% of bowel cancer cases in the UK are caused by overweight and obesity.[3]

Body-mass index (BMI)

Colon cancer risk is 18% higher in men who are overweight (body mass index [BMI] 25-29.9) and 48% higher in men who are obese (BMI 30+), compared with men of a normal weight (BMI 18.5-24.9), a meta-analysis showed.[4] Colon cancer risk is 12% higher in women who are obese, compared with women of a normal weight, a meta-analysis showed.[4] There is no association with rectal cancer in overweight women;[4] the association in obese women may be stronger in premenopausal than postmenopausal women.[5]

Rectal cancer risk is 6% higher in men who are overweight and 25% higher in men who are obese, compared with men of a normal weight, a meta-analysis showed.[4] There is no association between BMI and rectal cancer in women.[4]

Bowel cancer risk among men is 10% higher per 5 BMI units gained during adulthood, a meta-analysis showed.[6] Bowel cancer risk among women is not associated with weight gain during adulthood.[6]

Bowel adenoma risk is 47% higher in people who are obese by BMI compared with those who are healthy-weight, a meta-analysis showed.[7]

Waist circumference

Bowel cancer risk is 46% higher in people with the largest waist circumference, versus those with the smallest, a meta-analysis showed.[8]

Bowel adenoma risk is 39% higher in people with the largest waist circumference, versus those with the smallest, a meta-analysis showed.[9]

International Agency for Research on Cancer (IARC) and World Cancer Research Fund/American Institute for Cancer Research (WCRF/AICR) classify the role of this risk factor in cancer development.[1,2] 6% of bowel cancer cases in the UK are caused by alcohol drinking.[3]

Bowel cancer risk is 17% higher in people who consume around 12.5-50g (1.5-6 units) of alcohol per day, and 33% higher in those who consume 50g+ (6+ units) of alcohol per day, compared with non-/occasional drinkers, a meta-analysis showed.[4] Bowel cancer risk increases by 7% per unit of alcohol consumed per day.[5]

Bowel adenoma risk is 27% higher in people who drink around 3 units per day, a meta-analysis showed; the association is limited to colon adenoma, not rectal.[6]

International Agency for Research on Cancer (IARC) classifies the role of this risk factor in cancer development.[1] 7% of bowel cancer cases in the UK are caused by smoking.[2]

Bowel cancer risk is 17-21% higher in current cigarette smokers compared with never-smokers, meta-analyses of cohort studies have shown.[3-5] The association may be stronger in males than females, and stronger for rectal than colon cancer.[3-6]

Bowel cancer risk is 17-25% higher in former cigarette smokers compared with never smokers, meta-analyses have shown.[3-5]

Bowel cancer risk increases with the number of cigarettes smoked per day, by 7-11% per 10 cigarettes per day, a meta-analysis has shown.[4] Bowel cancer risk is higher in people who start smoking younger.[5]

Adenomatous bowel polyp risk is around twice as high in current smokers compared with never-smokers, a meta-analysis showed.[7]

Serrated bowel polyp risk is more than twice as high in current smokers compared with never- and ex-smokers, a meta-analysis showed.[8]

Diabetes

Bowel cancer risk among diabetics may vary by treatment type, though treatment type often relates to diabetes stage, which may further confound findings. Bowel cancer risk is lower in metformin users compared with non-users, meta-analyses have shown;[6-8]however this may be for women only.[9] Bowel cancer risk is not associated with insulin use compared with non-use, meta-analyses of cohort studies have shown.[10,11]

Inflammatory bowel disease

Bowel cancer risk is 70% higher in people with inflammatory bowel disease (IBD) (ulcerative or Crohn's colitis) compared with the general population, a meta-analysis showed.[12] Bowel cancer risk increases with extent and duration of IBD; patients who have IBD for 20 years or more have a 5% risk of developing bowel cancer.[12,13] Bowel cancer risk may vary by location of IBD lesions.[14]

Adenomas

Around 1% of people with larger (20mm+) adenomas, or adenomas with high-grade dysplasia, develop bowel cancer within around 4 years of having their adenomas removed, a pooled analysis showed.[15] Risk of advanced bowel cancer is 80% higher in people with low-risk polyps detected at first colonoscopy, compared with people with no polyps detected at first colonoscopy, a meta-analysis showed.[16]

Aspirin

Bowel cancer risk is 32-49% lower in people who have used aspirin daily for at least five years, compared with non-users, a meta-analysis showed.[17]

Bowel adenoma risk is 17% lower in people who used aspirin, compared with those who took a placebo, a meta-analysis of randomised control trials showed.[18]

International Agency for Research on Cancer (IARC) classifies the role of this risk factor in cancer development.[1] 2% of bowel cancer cases in the UK are caused by ionising radiation.[2]

Colon cancer risk is 53% higher in atomic bomb survivors compared with the general population, a cohort study has shown.[3]

Bowel cancer risk decreases with increasing age at radiation exposure.[4]Less than 1% of people chronically exposed to 0.1Gy radiation in early childhood will develop bowel cancer in their lifetime.[4]

Family history

Around 20% of bowel cancers are associated with hereditary factors other than Familial adenomatous polyposis (FAP) and Hereditary non-polyposis colorectal cancer (HNPCC).[1]

Bowel cancer risk is more than doubled in people with a first-degree relative (parent, sibling, child) with the disease, a meta-analysis showed.[2] Bowel cancer risk among people with a first-degree family history is higher in those with more than one affected relative, or a relative diagnosed at a younger age.[2,3]

Bowel adenoma risk is 70% higher in people with a first-degree relative with bowel cancer, a meta-analysis showed.[4]

Bowel cancer risk is not associated with having an adoptive parent with the disease, a cohort study showed; this may indicate genetic/biological factors rather than environmental factors underpin the familial risk.[5]

Familial adenomatous polyposis (FAP)

Familial adenomatous polyposis (FAP) accounts for less than 1% of bowel cancers.[6] Almost all FAP patients develop bowel cancer by age 40.[7]

Hereditary non-polyposis colorectal cancer (HNPCC)

Hereditary non-polyposis colorectal cancer (HNPCC) accounts for 1-4% of colon cancers.[6] Around 9 in 10 males and 7 in 10 females with HNPCC develop bowel cancer by age 70.[8]

BRCA1

BRCA1 mutations may account for some bowel cancers, particularly in younger women.[9]

World Cancer Research Fund/American Institute for Cancer Research (WCRF/AICR) classifies the role of this risk factor in cancer development.[1] 5% of bowel cancer cases in the UK are caused by too little physical activity.[2]

Colon cancer risk is 17-24% lower in the most physically active people, compared with the least physically active, meta-analyses of cohort studies have shown.[3-5]Colon cancer risk is 27% higher in the most sedentary people compared with the least, a meta-analysis of cohort studies showed.[6]

Rectal cancer risk is not associated with physical activity, a meta-analysis showed.[4]Rectal cancer risk is 6% higher in the most sedentary people compared with the least, a meta-analysis of cohort studies showed.[6]

Colon adenoma risk is 16% lower in the most physically active people, compared with the least physically active, a meta-analysis showed.[7]

Cancer stats explained

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